Coating device



M. v. HAMILTON 2,356,666

coATING DEVICE Filed May 14, 1942 2 Sheets-Sheet 1 Aug. 22, 1944.

Aug. 22, 1944. M. v. HAMILTON K 2,356,666

coATING DEVICE Filed May 14. 1942 2 Sheets-Sheet 2 INVENTOR f-M/w (n.

Patented Aug. 22, 1944 s'rA'rs. AEN

COATING DEVICE Merrill V. Hamilton, Gary, Ind. Application May 14, 1942, Serial No. 442,971

1 Claim.

This invention relates to improvements in coating devices for applying liquid coating to at products, such as steel sheets or strip, and more particularly for applying such coating to the under side of iiat sheets or strip during the flatwise horizontal travel thereof.

Black sheets and strip are frequently coated with substances forpreventing rust, for paint adherence, etc., the process thereof being known in the art as bonderizing. Generally, such coatings are applied by immersion or spraying, both of which processes have their disadvantages. For example, immersion requires considerable volume of solution, increasing the difficulty of maintaining concentrations and temperature, and spraying as formerly practiced, has been found quite unsatisfactory, particularly when attempting to spray theunder side of the at work.

It is an object of my invention to provide av coating device for separately treating the' under side,of the flat work, so arranged and disposed with respect to the travel of the work as to insure uniformity of treatment using a minimum amount of coating solution.

My invention contemplates supplying a liquid coating film or layer upon which the flat work is supported, as between adjacent rolls or conveying means, whereby the under side of the work is uniformly coated with the solution being used, the said support of the work by the solution being of particular advantage in coating thin gauge metal sheets and the like.

Additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. l is a cross sectional view illustrating an embodiment of my invention, said section being taken on the line I-I of Fig. 2; and

A Fig. 2 is a cross sectional view thereof taken on the line II-II of Fig. l.

Referring to the drawings, 2 designates the side walls or framework of a treatment tank or the like rotatably mounting a series of pairs of rubber-covered feed rolls 3 driven in any suitable manner for conveying a flat sheet or strip 4 through the apparatus.

My coating device is disposed between adjacent pairs of rolls 3 and includes a horizontal at plate 5 extends transversely of and spaced beneath beneath the rpath of travel of the sheet or strip 4 in parallel relation to the latter. Brackets 6 Aare secured to the ends of the plate andhave vertical slots 'l for adjustably supporting the plate from the walls or frame 2 as by bolts 8. y

Formed in the plate 5 and disposed transversely of the path of travel of the sheet or strip are a plurality of spaced discharge apertures 9,

said apertures beingfed by a common manifold or pipe I0 having registering openings therein, said manifold being disposed beneath and welded to the said lplate. The portion of the plate 5 extending beyond the locus of said apertures in the direction of travel of the sheet or strip is of sufficient dimension to permit the formation of a substantial layer or film of liquid coating solution supplied by the apertures, said layer being indicated by the arrowsin Fig. -1 and being created by the conjoint action of the flow from the apertures and the motion of the sheet or strip.

The liquid coating solution is fed to the manifold midway of the transverse length of plate 5, as by means of a flexible conduit II connected with a standpipe I2 through a control valve I3. Standpipe I2 maybe connected with a suitable source of supply of the solution under pressure, as' will be readily understood. As the sheets or strip 4 pass between the roll xpairs `3 with the coating solution flowing over the surface of plate 5, theunder surface of the sheet or strip contacts and is supported by the said layer, the ow of solution and movement of the sheet or strip effecting a uniform distribution of coating upon said under surface. As the liquid and sheet or strip reach the terminal edge of the plate 5, the liquid flows downwardly thereover whereupon it may be collected and returned to the source of supply for re-use. The supporting character of the liquid layer may be varied in accordance with the weight of the strip or sheet material, by Varying the flow of thel solution by valve I3 and by adjusting the spacing of the plate from the work, as by means 1, 8.

For the purpose of coating the upper surface of the sheet or strip 4, a conduit I4 may be connected with the supply standpipe I2, the said conduit I4 extending transversely over the path of travel of the sheet or strip and being provided with a plurality of spray apertures I5 for directing a spray of liquid therefrom downwardly onto the upper surface of the work.

Hence, it will be seen that I have provided for a complete coating treatment of .flat metal sheets or strip, wherein the upper surface thereof may be coated by the usual sprays, and wherein the under surface is uniformly coated by direct contact with a supporting layer of the liquid feed rolls, whereby the depth or weight of the y coating may be varied in accordance with the number of such devices, it being understood that the upper spray pipes I4 may likewise be employed for applying the coating solution to the upper surface of the sheets or strip.

It will be noted that my coating device is operable-With a minimum amount of the coating solution, which is of considerable advantage in use with solutions requiring temperature and concentration control thereof, since the solution may be continually -fed to the coating devices from a common source which may bek readily and uniformly controlled.

Various changes and modications will become apparent from the scope of the following claim.

I claim:

The combination with spaced means for supporting and conveying metal sheets or strip, of a coating device disposed therebetween, including a fiat plate extending transversely throughout and spaced beneath the path of the sheets or strip between said means, said plate having a series of apertures ltherein extending transversely of said path, means for supplying a liquid coating solution to the apertures for discharge of said solution between the plate and the sheets orI strip, means for varying the ow of said solution,

and means for adjustably .positioning the plate toward and away from the path of the, sheets or strip to vary the spacing between said plate and the under side of the sheets or strip, the said plate extending beyond the locus of the apertures in the direction of travel of the sheets or strip a distance suflicient to permit the formation of a layer of solution between sheets or strip and said plate.

MERRILL V. HAMILTON. 

